Classification
330 - Economics
618
333 - Economics of land & energy
515
600 - Technology
475
700 - The arts; fine & decorative arts
387
620 - Engineering & allied operations
365
000 - Computer science, information & general works
351
900 - History & geography
284
363 - Other social problems & services
224
380 - Commerce, communications & transportation
174
580 - Plants (Botany)
161
610 - Medicine & health
135
658 - General management
120
551 - Geology, hydrology & meteorology
91
500 - Natural sciences & mathematics
84
630 - Agriculture & related technologies
84
320 - Political science
72
140 - Specific philosophical schools
71
720 - Architecture
69
338 - Production
64
576 - Genetics & evolution
59
340 - Law
51
300 - Social sciences
45
530 - Physics
45
540 - Chemistry & allied sciences
45
370 - Education
40
414 - Phonology & phonetics
34
581 - Specific topics in natural history
26
800 - Literature & rhetoric
26
670 - Manufacturing
19
304 - Factors affecting social behavior
17
690 - Buildings
16
302 - Social interaction
15
657 - Accounting
13
331 - Labor economics
12
400 - Language
12
612 - Human physiology
12
621 - Applied physics
12
153 - Mental processes & intelligence
11
362 - Social welfare problems & services
11
361 - Social problems & social welfare in general
10
650 - Management & auxiliary services
10
100 - Philosophy & psychology
9
410 - Linguistics
9
170 - Ethics
7
624 - Civil engineering
6
350 - Public administration & military science
5
001 - Knowledge
4
005 - Computer programming, programs & data
4
158 - Applied psychology
4
381 - Commerce
4
more ...